What better way to compare two things, than to do it directly? By using similes, Le Guin doesn't beat about the bush when trying to make a point:

That's why we are all wearing these twelfth-century dresses that look so great on men and make women look either like a mushroom or a pregnant stork. (5)

She's got a point. Sure, some women might be able to pull it off, but for the most part, those graduation robes were designed with men in mind.